This invention relates to a swash plate type compressor. More particularly, it relates to a swash plate type compressor suitable for use in an air conditioner for an automobile, etc. in the form in which oil separated from a coolant gas is directly introduced into a slide part.
In general, the lubricating system of the swash plate type compressor is classified into two sorts; one having a forced lubricating device, and the other separating oil contained in a coolant gas circulating in a cooling cycle and then directly supplying it to sliding surfaces in the compressor. The former has an oil accumulating chamber below a cylinder block, and sucks up oil accumulated in the chamber by means of an oil pump or the like and then feeds it to respective slide parts. Therefore, the lubrication is reliable, but the apparatus becomes costly. The latter has the feature that the construction is very simple. On the other hand, however, when the compressor is held stopped for long, oil on the sliding surfaces of radial bearings, thrust bearings and a swash plate drops. This results in the disadvantage that the various parts are not satisfactorily lubricated at the restarting of the compressor and that the durability of the compressor is drastically spoiled.
According to Japanese Pat. No. 25733 published in 1974, a residual oil accumulating chamber is formed between the rear end face of a drive shaft and a valve plate. The residual oil accumulating chamber is connected with a main oil accumulating chamber which is formed in the bottom of a compressor. On the other hand, the residual oil accumulating chamber is connected with a thrust bearing by an oil passage penetrating through the shaft. Oil in the residual oil accumulating chamber is supplied to the thrust bearing owing to a centrifugal force which develops in the oil with the rotation of the shaft. Simultaneously therewith, oil in the main oil accumulating chamber is sucked up into the residual oil accumulating chamber. With the construction disclosed in this prior art, the force for sucking up into the residual oil accumulating chamber the oil which exists in the main oil accumulating chamber located below the residual oil accumulating chamber is the centrifugal force bestowed on the oil with the rotation of the shaft. Therefore, in case where the rotational frequency of the shaft is low, it is feared that the oil will not be sufficiently sucked up. It is also feared that the oil in the residual oil accumulating chamber will drop into the main oil accumulating chamber during the stop of the compressor and that the lubrication of the thrust bearing and the swash plate will not be satisfactorily executed at the restarting.